Housing, in particular for a heat exchanger, and method of its production

ABSTRACT

The application relates to a housing, in particular for a heat exchanger in an exhaust system of a motor vehicle, comprising a jacket with two joining margins which are joined along a joining line, the jacket having two connecting openings formed by recesses in the joining margins. The application also relates to a method of producing a housing by means of the following steps: First it is determined under which angle relative to each other two connecting openings of the housing are to be arranged with respect to a central line of the housing. Then the shape of a jacket is determined, taking into account the axial distance between the connecting openings. Subsequently the jacket is cut out from a sheet of material, with recesses which later form the connecting openings being cut out on at least one of two joining margins which later are adjoining each other. Thereafter the jacket is bent such that the two joining margins rest at each other. Finally the joining margins are connected with each other.

CROSS-REFERENCE

Foreign priority is hereby claimed under 35 U.S.C. §119 to DE 10332537.9which was filed in the Federal Republic of Germany on Jul. 17, 2003 andis incorporated by reference herein.

FIELD OF THE DISCLOSURE

The invention relates to a housing, in particular for a heat exchangerin an exhaust system of a motor vehicle, as well as to a method ofproducing such a housing.

BACKGROUND OF THE DISCLOSURE

With a housing of this type there is often the problem that connectionsfor a component arranged in the housing, for instance for the heatexchanger, are to be led through out of the housing in differentorientations. A very good example for this are the housings of heatexchangers used in the exhaust line of a motor vehicle. The heatexchangers mostly serve for taking away heat from the exhaust stream,which heat for instance can be used to heat the interior space of themotor vehicle. Although a high number of units of the heat exchangers isdemanded, the number of units of each individual embodiment which has tobe made available comparably low. This is due to the fact that theconnections of the heat exchanger have to be individually arranged withevery type of vehicle where such a heat exchanger is employed. Thisresults in that a multitude of differing housing types has to be madeavailable. The costs per unit are increased thereby.

It is the object of the invention to provide a housing which on the onehand has an as simple a construction as possible, so that themanufacturing costs will be low, and on the other hand allows a highflexibility with respect to the orientation of the connections that areto be passed through it. It is also the object of the invention toprovide a method of producing such a housing.

SUMMARY OF THE DISCLOSURE

In order to solve this object there is provided a housing, in particularfor a heat exchanger in an exhaust system of a motor vehicle, comprisinga jacket with two joining margins which are joined along a joining line,the jacket having two connecting openings formed by recesses in thejoining margins. The jacket can be cut or stamped for example from sheetmetal with low expenditure. In a technically simple manner, theconnecting openings are formed by recesses in the joining margins. In sodoing, almost any orientation of the connecting openings can be achievedby a suitable selection of the shape of the jacket. If with acylindrical housing the two connecting openings lie on the same radius,when viewed along a longitudinal axis of the housing, i.e. are arrangedon a generatrix of the jacket, then the jacket has the shape of arectangle, so that the joining line formed by the joining marginsextends in parallelism to the central line of the jacket. In case thatthe two connecting openings are arranged so as to have a rotationaloffset relative to each other, however, the jacket can be made so as tohave such a shape that the joining line extends oblique relative to thecentral line, for instance in the nature of a helical line about thecylinder-shaped jacket, with the pitch of the helical line beingselected such that the two connecting openings lie on the joining line.

In order to solve the above-mentioned object there is also provided amethod of producing a housing by means of the following steps: First itis determined under which angle relative to each other two connectingopenings of the housing are to be arranged with respect to a centralline of the housing. Then the shape of a jacket is determined, takinginto account the axial distance between the connecting openings.Subsequently the jacket is cut out from a sheet of material, withrecesses which later form the connecting openings being cut out on atleast one of two joining margins which later are adjoining each other.Thereafter the jacket is bent such that the two joining margins rest ateach other. Finally the joining margins are connected with each other.This method always uses the same method steps independently of therespective arrangement of the connecting openings, so that the methodcan be performed at favourable costs. It would even be conceivable tomanufacture different embodiments of the housing on one and the sameproduction line in direct succession, as these only differ in terms ofthe form of the blank of the jacket. The various cuts to size can beperformed in a flexible manner by laser cutting, for instance.

Advantageous designs of the invention will be apparent from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained in the following with the aid of twoembodiments illustrated in the attached drawings in which:

FIG. 1 shows in a top view a housing with an inserted heat exchangeraccording to a first embodiment of the invention;

FIG. 2 shows in a top view a housing with an inserted heat exchangeraccording to a second embodiment of the invention;

FIG. 3 shows a first step during production of the housings according tothe invention;

FIG. 4 shows a second step during production of the housing according tothe first embodiment;

FIG. 5 shows a second step during production of the housing according tothe second embodiment;

FIG. 6 shows a further step during production of the housings accordingto the invention; and

FIG. 7 shows a section along plane VII-VII of FIG. 1.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a housing 10 which receives a heat exchanger 5 arranged inthe interior of the housing and indicated in broken lines. The heatexchanger has two connecting sleeves 7 which can be connected with aheat exchanger circuit (not illustrated).

A component of the housing 10 is a jacket 12 which is cylindrical andhas a central line M. When laid out flat in a plane, the jacket 12 hasthe shape of a parallelogram. The jacket 12 is formed in that it hasbeen bent into the cylindrical shape and two opposite edges—designatedas joining margins 14, 16—have been connected with each other. The lineof contact of the two joining margins 14, 16 defines a joining linealong which the two joining margins 14, 16 are welded to each other.This is symbolised by a weld seam 18. The two remaining margins of theparallelogram each define a front face 20 to which a (not illustrated)cover member can be mounted. Then the housing will be completely closed.

For the passage of the connecting sleeves 7 through the housing, thereare provided two connecting openings 24 formed by two opposite recesses26, 28 in the joining margins 14, 16. The connecting openings 24approximately have the shape of a circle so that each recess 26, 28 ismore or less semicircular. It is to be seen that the diameter of theconnecting openings 24 is larger that the diameter of the connectingsleeves 7. In this way there is realised a sufficient intermediate spacebetween the connecting openings and the connecting sleeves, allowing arelative movement between heat exchanger 5 and housing 10 underdiffering thermal expansions.

With the embodiment according to FIG. 1, the joining line formed by thejoining margins 14, 16 extends in parallelism to the central line M. Inother words, the joining line corresponds to a generatrix of thecylindrical area of the jacket. It follows that the parallelogram shapeof the laid-out jacket 12 is a rectangle. In the embodiment according toFIG. 2, however, the jacket 12 has the shape of a “conventional”parallelogram, where the corner angles are different in pairs. Thejoining line between the joining margins 14, 16 accordingly extendsabout the jacket as a helical line, i.e. extends oblique relative to thecentral line M. Therefore the connecting openings 24 are not any longeron one and the same radius with respect to the central line M, as is thecase with the embodiment according to FIG. 1, but are on differentradii. In the embodiment shown in FIG. 2 the two connecting sleeves 7are aligned so as to have a 90° rotational offset relative to eachother.

The production of the housing will now be explained with the aid of theFIGS. 3 to 7.

In a first step, a sheet of material 30 will be prepared (see FIG. 3).The jacket 12 will be cut out from this sheet at a later point in time.Advantageously sheet metal is used the properties of which are adaptedto the expected application conditions of the housing.

In an intermediate step the parallelogram shape of the jacket 12 isdetermined. If there is to be produced a housing according to FIG. 1,for instance, the outline of the jacket is defined as the shape shown inFIG. 4, namely as a rectangle having the recesses 26, 28. If, on theother hand, a housing according to FIG. 2 is to be produced, the outlineof the jacket is defined as the shape shown in FIG. 5, namely as a“conventional” parallelogram. The angle α, by which the corner angles ofthe parallelogram are larger or smaller than 90°, can be determinedeasily as a function of the desired rotational offset of the twoconnecting openings 24 relative to each other in the circumferentialdirection, of the distance A between the two connecting openings inaxial direction as well as of the circumference B of jacket 12.

When the contour of jacket 12 has been determined, the latter is cutfrom the sheet of material 30, as is shown in FIGS. 4 or 5.

In a next method step, the cut-out jacket 12 is bent around the heatexchanger 5 (see FIG. 6) so that the sleeves 7 come to lie in theconnecting openings 24 formed by the recesses 26, 28. An insulation anddamping material can be arranged between jacket 12 and heat exchanger 5.

According to an alternative method the cut-out jacket 12 is first bentso as to take up its final shape. Then the heat exchanger, wrapped up inthe insulation layer, is inserted into the jacket which is slightlyre-opened for that purpose. Subsequently the jacket is closed again (thespring-back of the material may possibly be sufficient for this), andthe joining margins are connected with each other.

Finally the joining margins 14, 16 are connected with each other throughweld seam 18 (see FIG. 7). Thus, the jacket 12 of the housing will beclosed. In practice, the two joining margins 14, 16 in most cases willnot be butt-jointed with each other, but rest at each other with anoverlap. In this way the tolerances of the jacket and of the heatexchanger can be easily compensated. Moreover, welding the joiningmargins to each other is facilitated.

Cover members can then be mounted to the front faces 20 of the cylinderformed by the jacket 12. The housing is then completely closed off.Through the orientation of the jacket 12 relative to the cover members,i.e. by rotation about axis M, the orientation of the connecting sleeves7 can be adjusted as desired.

According to a (not illustrated) further embodiment the connectingopenings 24 can each be constituted by a single recess provided only onone of the two joining margins 14, 16. Here, the two recesses can eitherbe provided in only one of the joining margins, or there is one recessin each joining margin.

A particular advantage of the housing and the method according to theinvention is that the connecting sleeves 7 can be readily mounted, inparticular welded, to the heat exchanger 5 prior to its insertion in thehousing 10. As the sleeves 7 are easily accessible, there are no qualityproblems on providing the respective weld seams. Moreover, theconnecting sleeves 7 can be welded to the heat exchanger 5 in anyorientation, as is shown in FIG. 1. In connection with the variableorientation of the connecting sleeves 7 relative to each other, amaximum freedom arises in terms of connecting the heat exchanger with aheat exchanger circuit. Of course, the connecting sleeves can also beconfigured so as to be straight or bent with an angle other than 90°.

With both embodiments there has been illustrated as an example acylindrical housing with a jacket in the shape of a parallelogram,because this is better to understand than more complicated geometricshapes. Basically the principle according to the invention may beapplied to housings of any cross-section, for instance oval orrectangular, even with a changing cross-section. The jacket basicallycan have any shape; the only condition is that this shape when benttogether encloses the heat exchanger and can be closed along a joiningline on which the connecting sleeves are provided. The joining marginsdo not have to be straight, but may extend with a curvature, resultingin a correspondingly curved extension of the joining line.

1. A housing, in particular for a heat exchanger in an exhaust system ofa motor vehicle, comprising a jacket with two joining margins which arejoined along a joining line, the jacket having two connecting openingsformed by recesses in the joining margins.
 2. The housing according toclaim 1, characterised in that the connecting openings consist of twoopposite recesses in the joining margins.
 3. The housing according toclaim 1, characterised in that the joining margins are welded to eachother.
 4. The housing according to claim 1, characterised in that theconnecting openings are arranged in different angular orientations whenviewed along a central line of the housing.
 5. The housing according toclaim 1, characterised in that the jacket is made from sheet metal. 6.The housing according to claim 1, characterised in that the jacket isconnected at its front faces to one cover member each.
 7. The housingaccording to claim 1, characterised in that the jacket, when laid outflat, has a parallelogram shape.
 8. The housing according to claim 1,characterised in that it is cylindrical.
 9. A method of producing acylindrical housing, comprising: it is determined under which anglerelative to each other two connecting openings of the housing are to bearranged with respect to a central line of the housing; the shape of ajacket is determined, taking into account the axial distance between theconnecting openings; the jacket is cut out from a sheet of material,with recesses which later form the connecting openings being cut out onat least one of two joining margins which later are adjoining eachother; the jacket is bent such that the two joining margins rest at eachother; the joining margins are connected with each other.
 10. The methodaccording to claim 9, characterised in that the jacket is cut out fromsheet metal.
 11. The method according to claim 10, characterised in thatthe jacket is punched out.
 12. The method according to claim 10,characterised in that the jacket is laser cut.
 13. The method accordingto claim 9, characterised in that the two joining margins are welded toeach other.
 14. The method according to claim 9, characterised in thatafter bending the jacket, a heat exchanger is inserted by slightlyre-opening the jacket for a short time.
 15. The method according toclaim 14, characterised in that the heat exchanger is provided withconnecting sleeves.
 16. The method according to claim 15, characterisedin that the connecting sleeves are welded to the heat exchanger in anorientation which is adapted to the particular application conditions.